The statements in this section merely provide background information related to the present disclosure. Accordingly, such statements are not intended to constitute an admission of prior art.
Diesel engines can operate on a 100% diesel supply of fuel. Additionally, diesel engines can be configured to operate partially or fully on a biodiesel supply of fuel. A biodiesel blend ratio can be identified. B0 fuel is identified as a 100% diesel supply of fuel. B100 fuel is identified as 100% biodiesel supply of fuel. Bx fuel can be identified with x % biodiesel composition and (100%-x %) diesel composition. For example, B40 fuel is a 40% biodiesel and 60% diesel composition.
Diesel fuel and biodiesel fuel include different properties. Diesel fuel has a higher energy density than biodiesel fuel. As a result, in order to achieve a substantially identical result in combustion, a greater mass of biodiesel needs to be injected than would be required of diesel under the same circumstances. Use of fuel in combustion can be adjusted based upon the biodiesel blend ratio. Further, wherein fuel is utilized for other purposes than combustion within the engine, the mass of fuel utilized similarly must be adjusted based upon the biodiesel ratio.
One use of fuel includes regeneration of a lean NOx trap (LNT). NOx is a component of an exhaust gas flow generated by the engine during combustion. Aftertreatment devices are known to treat NOx within the exhaust gas flow, converting the NOx into other substances to be expelled with the exhaust. An LNT includes chemicals that store NOx emissions during engine operations generating NOx and allow release of the stored NOx during fuel rich conditions. The LNT has limited storage capacity and must be regenerated with a fuel rich reducing “pulse” as it nears capacity. It is desirable to control the efficiency of the regeneration event o provide optimum emission control and while maintaining minimum fuel consumption.